Baby Silkies poop stuck

Baby Silkies have poop stuck to there rear ends. its large and hard and it looks like its blocking the butt. we had one die. we tried to clean them and they look better. but what is causing it? any help please. oh they are 1 week old today.

If you check out the learning center you will find info on pastie but and chick issues.
I put some sand from the big girl coop in with the babies and didn't have any issues with pastie but. (knock on wood)
Try a dish of sand and keep checking those little bums!
Pastie but can kill your babies.
good luck
Patricia